Triceps brachii

Muscle parts

Latin name

Musculus triceps brachii

Latin muscle parts

Caput longum; Caput laterale; Caput mediale or profundum

Group

Brachial muscle – posterior compartment

Etymology

In English, the muscle’s name is the three-headed muscle of the arm.The term triceps comes from the Latin words tris meaning “two” and caput meaning “head.”The Latin term brachium derives from the Greek brachion meaning “arm,” in reference to the region of the upper limb between the shoulder and the elbow.

Origin

Infraglenoid tubercle of scapula and joint capsule of the shoulder (long head), oblique ridge in the upper half of the posterior humeral shaft (lateral head), posterior and medial surfaces of the humeral shaft below the point of insertion of the teres major to just proximal to the trochlea (medial head)

Insertion

Upper surface of the olecranon process of ulna and the antebrachial fascia

Action

Extension of the elbow joint; assist with extension of the shoulder especially when the arm is flexed; long head helps stabilize the bottom of the shoulder joint

Nerve supply

Radial nerve (C6, C7, and C8)

Blood supply

From proximal to distal, the muscle receives blood from the posterior circumflex humeral artery, muscular branches from the profunda brachii artery, the superior and inferior ulnar collateral arteries, and the recurrent interosseous artery.